The UTSW-SLE-CORT Flow Cytometry Core will operate within the existing infrastructure of the Rheumatology Division, the Harold C. Simmons Arthritis Research Center and the Center for Immunology to support the research activities of Project investigators. The individual research programs proposed in the UTSW-SLE-CORT have common requirements for reagents and services. The Core will consist of a Director and a Research Technician. The Core will utilize the Director's laboratory for preparation of samples and for experiments. The Flow Cytometry Core will employ flow cytometry instruments that are currently available at UT Southwestern Medical Center. The proposed activities of the Core will be to provide custom reagents and services that would not otherwise be available for the individual laboratories of the UTSW-SLE-CORT. The specific aims of the Flow Cytometry Core are:(1) to develop standardized protocols for flow cytometric assays;(2) to generate fluorochrome-labeled antibodies and provide quality control for the flow cytometric assays;and (3) to establish a data archiving system for flow cytometry data. In the first aim the Core will develop antibody panels for the identification of murine (Project 1) and human (Projects 2, 3 and 4) SLAM family members, activation markers and intracellular molecules for B, T, NK, dendritic cell (DC) and myeloid cell subsets. We will work with project investigators to develop and optimize protocols for cell preparation and storage, kinetics of cell responses for phospho-protein assays, and polychromatic immunophenotyping assays. Of import, the same reagents and protocols can be utilized for the identification of many murine and human intracellular molecules including phospho-proteins. The goal of this aim is to develop and implement protocols that will result in the generation of maximum information from limited murine lupus and human SLE patient samples. In the second aim, the Core will generate appropriately labeled antibodies with novel fluorochromes for complex polychromatic flow cytometric assays. The flow cytometry core will provide routine quality control checks of the antibodies, protocols and assays for project investigators of the UTSW- SLE-CORT. In the third aim, the Core will assist project investigators with data analysis and establish a mechanism to archive unprocessed data. Another objective of this aim is to facilitate communication concerning optimized protocols and potentially important new observations between project investigators.